Pairwise Nucleotide Sequence Identity Research Articles

Characterization, Amplification, and Phylogenetic Analysis of Gossypium herbaceum Using rbcL Molecular Marker

People have used medicinal plants for centuries to produce traditional remedies that greatly interest modern health care. One of these plants, Gossypium herbaceum or commonly called Arabian cotton, has been used in various medicinal applications. Scientists are turning to DNA barcoding, a molecular technique that identifies species using standardized DNA regions. Objective: To evaluate samples of Gossypium herbaceum and their physical properties. Methods: DNA was extracted from the plant material, and its quality and quantity were checked. Using PCR and gel electrophoresis, amplification of the RBCL gene was done. Purification of the PCR products was done for DNA sequencing. After that, all the DNA sequences were compared with the available DNA sequences in public databases. The relationship between Gossypium herbaceum and other related species was evaluated using the neighbour-joining method for phylogenetic analysis. Results: The results showed a high percentage of pairwise nucleotide sequence identity with Gossypium richmond and Gossypium hirsutum. The study demonstrated the potential of DNA barcoding using the rbcL gene as a reliable method for identifying and confirming Gossypium herbaceum. Also, this study provides valuable insight into the phylogenetic relationships of this medicinal plant species. Conclusions: The findings support the conservation and appropriate use of medicinal plants and highlight the importance of ensuring the authenticity and quality of herbal products.

Identification and molecular characterization of cotton leaf curl Gezira betasatellite and two distinct begomoviruses infecting papaya trees in the Kingdom of Saudi Arabia

Begomovirus is the largest genus in the family Geminiviridae and constitutes more than 445 virus species. Begomoviruses are characterized by single-stranded circular genomes with monopartite or bipartite components and transmitted by whitefly (Bemisia tabaci). Begomoviruses cause severe diseases in many economically important crops throughout the world. Typical symptoms of a begomovirus infection including severe leaf curling, vein thickening, vein darkening and reduced leaf size were observed in papaya plants in the Dammam district of the Eastern Province of Saudi Arabia during the growing season in 2022. A total of 10 samples were collected, and total genomic DNA was isolated from naturally infected papaya tree samples and subjected to PCR amplification using universal diagnostic primers for begomoviruses and associated satellites. Three PCR-amplified genomic components of begomoviruses and betasatellite namely P61Begomo (645 bp), P62Begomo (341 bp) and P62Beta (563 bp) were sent for Sanger DNA sequencing to Macrogen Inc. These partial viral genome sequences were submitted to Genbank database and accession numbers ON206051, ON206052 and ON206050 were assigned to P61Begomo, P62Begomo and P62Beta respectively. Phylogenetic analysis and pairwise nucleotide sequence identity studies identified P61Begomo was identified as Tomato yellow leaf curl virus, P62Begomo as DNA A component of a bipartite begomovirus Watermelon chlorotic stunt virus and P62Beta as begomovirus associated betasatellite; Cotton leaf curl Gezira betasatellite. To the best of our knowledge, this is the first report of a begomovirus complex infecting papaya (Carica papaya) in the Kingdom of Saudi Arabia.

Identification of diverse novel genomoviruses in gut of wild birds

Genomoviridae is a virus family belonging to circular replication associated protein encoding ssDNA (CRESS-DNA) viruses, which have diverse genomic architecture and are widely distributed among different ecosystems. In this study, we characterized 39 novel genomovirus genomes including 3 from wild egrets, 9 from wild cranes, as well as 27 from wild finches in three different types of cloacal swabs of wild bird sampled in the station of Xinqing bird ringing, Maoershan Nature Reserve in Heilongjiang Province, Changbai Mountain in Jilin Province, and Hangzhou Wetland Park in Zhejiang Province, China. Here, using a Rep sequence phylogeny-based analysis, we divided the 39 genomoviruses into 8 genera within the family Genomoviridae, including Gemycircularvirus (n=20), Gemykibivirus (n=3), Gemygorvirus (n=2), Gemyvongvirus (n=2), Gemykolovirus (n=3), Gemykrogvirus (n=6), Gemytondvirus (n=1), Gemyduguivirus (n=1) and one unclassified genomovirus. The 39 genomovirus genomes belong to 36 species (27 of which are new) based on the currently accepted genomovirus pairwise nucleotide sequence identity species demarcation threshold of 78%. Overall, the research enriches our knowledge of CRESS-DNA viral diversity in China and emphasizes the prevalence of genomoviruses in nature.

Comparative genomic analysis of eutherian connexin genes

The eutherian connexins were characterized as protein constituents of gap junctions implicated in cell-cell communications between adjoining cells in multiple cell types, regulation of major physiological processes and disease pathogeneses. However, conventional connexin gene and protein classifications could be regarded as unsuitable in descriptions of comprehensive eutherian connexin gene data sets, due to ambiguities and inconsistencies in connexin gene and protein nomenclatures. Using eutherian comparative genomic analysis protocol and 35 public eutherian reference genomic sequence data sets, the present analysis attempted to update and revise comprehensive eutherian connexin gene data sets, and address and resolve major discrepancies in their descriptions. Among 631 potential coding sequences, the tests of reliability of eutherian public genomic sequences annotated, in aggregate, 349 connexin complete coding sequences. The most comprehensive curated eutherian connexin gene data set described 21 major gene clusters, 4 of which included evidence of differential gene expansions. For example, the present gene annotations initially described human CXNK1 gene and annotated 22 human connexin genes. Phylogenetic tree calculations and calculations of pairwise nucleotide sequence identity patterns proposed revised and updated phylogenetic classification of eutherian connexin genes. Therefore, the present study integrating gene annotations, phylogenetic analysis and protein molecular evolution analysis proposed new nomenclature of eutherian connexin genes and proteins.

The complete mitochondrial genome of Echinostoma miyagawai: Comparisons with closely related species and phylogenetic implications

Echinostoma miyagawai (Trematoda: Echinostomatidae) is a common parasite of poultry that also infects humans. Es. miyagawai belongs to the “37 collar-spined” or “revolutum” group, which is very difficult to identify and classify based only on morphological characters. Molecular techniques can resolve this problem. The present study, for the first time, determined, and presented the complete Es. miyagawai mitochondrial genome. A comparative analysis of closely related species, and a reconstruction of Echinostomatidae phylogeny among the trematodes, is also presented. The Es. miyagawai mitochondrial genome is 14,416 bp in size, and contains 12 protein-coding genes (cox1–3, nad1–6, nad4L, cytb, and atp6), 22 transfer RNA genes (tRNAs), two ribosomal RNA genes (rRNAs), and one non-coding region (NCR). All Es. miyagawai genes are transcribed in the same direction, and gene arrangement in Es. miyagawai is identical to six other Echinostomatidae and Echinochasmidae species. The complete Es. miyagawai mitochondrial genome A + T content is 65.3%, and full-length, pair-wise nucleotide sequence identity between the six species within the two families range from 64.2–84.6%. The Es. miyagawai sequences is most similar to Echinostoma caproni. Sequence difference are 15.0–33.5% at the nucleotide level, and 8.6–44.2% at the amino acid level, among the six species, for the 12 protein-coding genes. ATG and TAG are the most common initiation and termination codons, respectively. Twenty of the Es. miyagawai transfer RNA genes transcribe products of the conventional cloverleaf structure, while two of the transfer RNA genes, namely trnS1(AGC) and trnS2(UGA), have unpaired D-arms. Phylogenetic analyses using our mitochondrial data indicate that Es. miyagawai is closely related to other Echinostomatidae species, except for Echinostoma hortense, which forms a distinct paraphyletic branch, and Echinochasmus japonicus, which is outside the clade containing all other Echinostomatidae species. These phylogenetic results support the elevation of subfamily Echinostomatidae. Our dataset also provides a significant resource of molecular markers to study the taxonomy, population genetics, and systematics of the echinostomatids.

ICTV Virus Taxonomy Profile: Papillomaviridae.

The Papillomaviridae is a family of small, non-enveloped viruses with double-stranded DNA genomes of 5 748 to 8 607 bp. Their classification is based on pairwise nucleotide sequence identity across the L1 open reading frame. Members of the Papillomaviridae primarily infect mucosal and keratinised epithelia, and have been isolated from fish, reptiles, birds and mammals. Despite a long co-evolutionary history with their hosts, some papillomaviruses are pathogens of their natural host species. This is a summary of the International Committee on Taxonomy of Viruses (ICTV) Report on the taxonomy of the Papillomaviridae, which is available at http://www.ictv.global/report/papillomaviridae.

Invasion of previously unreported dicot plant hosts by chickpea chlorotic dwarf virus in Pakistan.

Members of the genus, Mastrevirus (family, Gemniviridae) transmitted by leafhopper vectors infect monocotyledonous or dicotyledonous plants, and infection of agricultural crops results in reduced yield and quality. During 2012, a study was undertaken in the Punjab and Sindh Provinces in Pakistan to determine the identity of suspect geminiviruses associated with symptomatic cotton and vegetable plants exhibiting foliar enations, leaf curling, mosaic, and stunting reminiscent of geminivirus infection. To determine suspect geminiviral identity, fifteen apparently full-length mastrevirus genome (~ 2600 base pairs) were amplified by rolling-circle amplification, digested, cloned into the plasmid vector, pGEM-3Zf+, and sequenced from cucumber, Gossypium arboreum L., Gossypium hirsutum L., okra and tomato. The mastrevirus full-length genome sequences obtained shared their highest pairwise nucleotide sequence identity, at 97.3-98.6%, with previously reported C and L strains of Chickpea chlorotic dwarf virus (CpCDV) from chickpea and cotton in Pakistan, respectively. However, CpCDV has not been previously identified from cucumber, G. arboreum, okra, or tomato. The association of CpCDV with four previously unreported plant hosts suggests that CpCDV strains C and strain L have a broader than expected host range, and therefore may be found to negatively affect vegetable crops, particularly, when grown in proximity to cotton.

Alphasatellitidae: a new family with two subfamilies for the classification of geminivirus- and nanovirus-associated alphasatellites.

Nanoviruses and geminiviruses are circular, single stranded DNA viruses that infect many plant species around the world. Nanoviruses and certain geminiviruses that belong to the Begomovirus and Mastrevirus genera are associated with additional circular, single stranded DNA molecules (~1-1.4kb) that encode a replication-associated protein (Rep). These Rep-encoding satellite molecules are commonly referred to as alphasatellites and here we communicate the establishment of the family Alphasatellitidae to which these have been assigned. Within the Alphasatellitidae family two subfamilies, Geminialphasatellitinae and Nanoalphasatellitinae, have been established to respectively accommodate the geminivirus- and nanovirus-associated alphasatellites. Whereas the pairwise nucleotide sequence identity distribution of all the known geminialphasatellites (n=628) displayed a troughs at ~70% and 88% pairwise identity, that of the known nanoalphasatellites (n=54) had a troughs at ~67% and ~80% pairwise identity. We use these pairwise identity values as thresholds together with phylogenetic analyses to establish four genera and 43 species of geminialphasatellites and seven genera and 19 species of nanoalphasatellites. Furthermore, a divergent alphasatellite associated with coconut foliar decay disease is assigned to a species but not a subfamily as it likely represents a new alphasatellite subfamily that could be established once other closely related molecules are discovered.

The Distribution of Miniature Impala Elements and SIX Genes in the Fusarium Genus is Suggestive of Horizontal Gene Transfer

The mimp family of miniature inverted-repeat transposable elements was previously found only in genomes of Fusarium oxysporum and is contextually associated with virulence genes in this species. Through extensive comparative analysis of 83 F. oxysporum and 52 other Fusarium genomes, we uncovered the distribution of different mimp families throughout the genus. We show that (i) mimps are not exclusive to F. oxysporum; (ii) pathogenic isolates generally possess more mimps than non-pathogenic strains and (iii) two isolates of F. hostae and one F. proliferatum isolate display evidence for horizontal transfer of genetic material to or from F. oxysporum. Multiple instances of mimp elements identical to F. oxysporum mimps were encountered in the genomes of these isolates. Moreover, homologs of effector genes (SIX1, 2, 6, 7, 11 and FomAVR2) were discovered here, several with very high (97–100%) pairwise nucleotide sequence identity scores. These three strains were isolated from infected flower bulbs (Hyacinthus and Lilium spp.). Their ancestors may thus have lived in close proximity to pathogenic strains of F. oxysporum f. sp. hyacinthi and f. sp. lilii. The Fo f. sp. lycopersici SIX2 effector gene was found to be widely distributed (15/18 isolates) throughout the F. fujikuroi species complex, exhibiting a predominantly vertical inheritance pattern. These findings shed light on the potential evolutionary mechanism underlying plant-pathogenicity in Fusarium and show that interspecies horizontal gene transfer may have occurred.

Molecular variability in the cysteine rich protein of potato virus M.

The potato virus M (PVM), belonging to the genus Carlavirus, is a worldwide endemic pathogen in potato fields. p11 is an 11-16kDa protein encoded by the last open reading frame of PVM which contains cysteine rich proteins (CRPs) motif. CRPs have been identified as suppressors of gene silencing. In this study the p11 gene from 28 PVM isolates, including 16 new isolates from Iran, were used to determine the global genetic structure of PVM populations. Pairwise nucleotide sequence identity scores showed that global PVM CRP sequence similarity was between 69.3 and 100%. This genetic diversity divided the 28 isolates into two main divergent phylogenetic clades. The rate of genetic diversity and non-synonymous to synonymous mutations (dN/dS) were significantly different between these two clades. Analysis showed that PVM CP is under significant negative selection pressure with the global ω value of 0.260.

Spotted Fever Group Rickettsiae in Questing Ticks, Central Spain

Spotted Fever Group Rickettsiae in Questing Ticks, Central Spain

Scalp Eschar and Neck Lymphadenopathy Caused byRickettsia massiliae

Scalp Eschar and Neck Lymphadenopathy Caused by<i>Rickettsia massiliae</i>

Fulfilling Koch’s postulates for beet curly top Iran virus and proposal for consideration of new genus in the family Geminiviridae

Beet curly top Iran virus (BCTIV) is a divergent geminivirus with biological properties similar to those of curtoviruses; however, the virus is distinct from curtoviruses phylogenetically and in its genome organisation. The replication-associated protein is phylogenetically more closely related to those of mastreviruses than to those of curtoviruses whereas the capsid protein shares high amino acid sequence identity (77-83%) with those of curtoviruses. The 17 BCTIV genomes from Iran share ~77% pairwise nucleotide sequence identity with spinach curly top Arizona virus (SCTAV) from Arizona, USA, which was characterised recently. To demonstrate the infectivity of the monopartite BCTIV genome and to fulfil Koch's postulates, an infectious clone was constructed using a dimer of the full-length genome of an isolate from this study - BCTIV-[IR:Neg:B33P:Sug:08]. Agroinoculation with the cloned DNA resulted in the efficient infection of 74% of sugar beet plants, which resulted in curly top symptoms. The curly top infection of agroinoculated plants was successfully transmitted to 80% of healthy sugar beet plants by the natural BCTIV vector, Circulifer haematoceps. Since BCTIV and SCTAV share <62% pairwise nucleotide sequence identity with all other geminiviruses and have unique genome architectures and properties, and since this is coupled with phylogenetic support at the full-genome level and that of it proteins, we propose that they should be re-classified as members of a new genus, "Becurtovirus", in the family Geminiviridae.

First Report and High Prevalence in Noncherry Host of Cherry virus A in Italy

Cherry virus A (CVA) has been reported to naturally infect sweet and sour cherry, apricot, peach, and plum but has not been associated with any symptoms. In the spring and summer of 2005, samples were collected in Prunus spp. germplasm collections in Campania (Italy) and analyzed by a polyvalent reverse transcription-polymerase chain reaction (RT-PCR) assay (1). Amplicons were sequenced, revealing CVA infection in seven apricot cultivars (Prunus armeniaca L.), one plum (Prunus domestica L.), and one cherry (Prunus avium L.). CVA sequences (GenBank Accession Nos. DQ445275 to DQ445292) compared among themselves and with databank sequences showed pairwise nucleotide sequence identity levels of 80.3 to 99.6% (86.8 to 100% for amino acid sequences), significantly extending the known variability range of CVA. The presence of CVA was confirmed by hybridization with a CVA-specific probe (P39) (2), targeting region different from that amplified in the polymerase chain reaction assay. All samples containing CVA were found to be in mixed infections with Apple chlorotic leaf spot virus (ACLSV) and Apricot pseudo-chlorotic leaf spot virus (plum, apricot), or ACLSV plus Cherry green ring mottle virus (cherry) so that CVA symptomatology could not be evaluated. To our knowledge, these results constitute the first report of the occurrence of CVA in Italy. They confirm the ability of CVA to naturally infect noncherry Prunus spp. hosts with surprisingly high prevalence levels (6 of 14 and 1 of 6 tested apricot and plum cultivars, respectively).

Characterization of DNAbeta associated with begomoviruses in China and evidence for co-evolution with their cognate viral DNA-A.

Eighteen samples of begomoviruses isolated from tobacco, tomato and weed species in Yunnan, China were found to be associated with DNAbeta molecules, for which the complete nucleotide sequences were found to contain 1333-1355 nt. The 18 DNAbeta molecules identified consist of three main types, each associated with a different begomovirus species: 72-99 % nucleotide identity was found within one type, but only 39-57 % identity was found between types. All the DNAbeta molecules reported here and elsewhere contain a 115 nt conserved region that has 93-100 % identity with a consensus sequence, and have a common ORF encoding 118 amino acids on the complementary strand (designated C1). Co-agroinoculation of the DNA-A component of Tomato yellow leaf curl China virus tobacco isolate Y10, with its associated DNAbeta (Y10beta), shows this DNAbeta to be involved in symptom induction in tobacco and tomato. The in-frame ATG mutation of C1 of Y10beta caused much milder symptoms as compared with wild Y10beta, indicating a functional role for this ORF. Pairwise nucleotide sequence identity comparisons of DNAbeta molecules and their cognate viral DNA-A molecules indicate that DNAbeta molecules have co-evolved with their cognate helper viruses. Recombination between DNAbeta molecules is documented and a DNAbeta species concept is proposed and discussed.

Evolutionary pathways of N2 neuraminidases of swine and human influenza A viruses: origin of the neuraminidase genes of two reassortants (H1N2) isolated from pigs

The complete nucleotide sequences of the neuraminidase (NA) genes of two reassortant (H1N2) and two H3N2 influenza A viruses isolated from pigs were determined and phylogenetic relationships between these and previously reported N2 NA genes were investigated. On the basis of pairwise nucleotide sequence identity, the NA genes of two reassortants, A/sw/Kanagawa/2/78 and A/sw/Ehime/1/80, were most closely related to those of human influenza A virus strains isolated in 1972 and the earliest available swine H3N2 influenza A viruses, respectively. Phylogenetic trees showed that the NA genes can be segregated into three groups, including lineages for (i) swine strains, (ii) the earliest human strain and (iii) recent human strains. The evolutionary tree for the 11 nucleotide and amino acid sequences suggested that the NAs of A/sw/HK/4/76 and A/sw/Kanagawa/2/78 belong to the lineage for recent human viruses. In contrast, the NA genes of the A/sw/HK/3/76 and H1N2 reassortant A/sw/Ehime/1/80 viruses were found to be of a swine lineage. The swine virus NA genes were further characterized by the cocirculation of two distinct lineages. Although the rates of synonymous (silent) substitutions for the swine and human viruses were nearly identical (0.00946 to 0.00884 per site per year), the rate of non-synonymous (amino acid changing) substitutions for swine virus NA genes was about 60% of that for the human virus.